As　concerns　grow　over　sustainable　development,　it　is　important　to　consider　properly　the　environmental　implications　of　using　fibre-reinforced　polymers　to　strengthen　concrete　structures.　Since　the　load　capacity　of　a　structure　has　an　effect　on　its　relative　environmental　impact,　an　energy-mechanical　index,　in　which　both　energy　consumption　and　mechanical　aspects　are　taken　into　account,　was　proposed　for　evaluating　the　integrated　environmental　performance　of　strengthening　solutions.　Life-cycle　assessment　was　used　to　evaluate　the　energy　use,　and　corresponding　experiments　were　designed　to　obtain　the　load　capacity　of　reinforced　concrete　beams　with　different　strengthening　solutions.　Moreover,　Monte　Carlo　simulation　was　adopted　to　analyse　the　parameter　uncertainty　of　the　life-cycle　assessment.　The　strengthening　experiments　indicated　that　the　carbon-fibre-reinforced-polymer　strengthening　solution　had　a　more　efficient　improvement　impact　on　load　capacity　compared　with　the　basalt-fibre-reinforced-polymer　solutions.　The　improvement　with　one　carbon-fibre　sheet　was　equivalent　to　that　with　two　basalt-fibre　sheets.　However,　the　carbon-fibre　strengthening　solution　consumed　more　energy　than　the　basalt-fibre　strengthening　solutions　due　to　its　high　embodied　energy.　In　addition,　the　energy-mechanical　index　of　the　basalt-fibre　strengthened　beams　was　far　lower　than　that　of　the　carbon　fibre　ones,　whether　the　determined　approach　or　the　probability-based　method　was　adopted,　indicating　the　superior　integrated　performance　of　the　basalt-fibre-reinforced-polymer　strengthening　solution.